This invention relates to storage receptacles or magazines for drill bits. The drill bits are primarily, but not exclusively, of small diameter and are particularly, but not exclusively, for use in drilling printed circuit boards (PCBs) where the diameter of the holes required is very fine, sometimes in the order of 2 to 4 mm in diameter and therefore the bits required for this function are very fine and fragile and easily damaged when being handled and also through use.
There are several disadvantages present in the handling of such drill bits either after initial manufacture or after regrinding. After manufacture, the drill bits are each provided with a tight fitting collar of eg. a plastics material, the collar being positioned at a pre-determined distance from the point of the drill. In the re-grinding process, the distance between the collar and the point is checked. After manufacture of re-grinding, the drill bits are normally placed in a box having a hinged lid. While there are holes in an insert in the box into which the stem of the bits are placed to hold the bits upright and the insert and lid have foamed material for the protection of the drill bits, due to their fragility, damage can be caused when closing the lid if care is not taken.
Heretofore, holes in PCBs are drilled in a group in a pre-set pattern when the chuck of a drill with a plurality of drill bits moves down towards the PCB. All bits should come into contact with the PCB simultaneously. Obviously, if one or more of the plurality of bits is out of position due to incorrect fitting into the chuck, damage prior to use, or due to damage through wear, then this could possibly cause damage to the PCBs through incorrect drilling of holes into the PCBs. Due to the bits being very fine, any damage to the bits cannot be seen unless each bit is magnified and examined. This is disadvantageous since it is labour intensive and therefore costly to have to examine the bits. It is also costly to continually having to take the drill out of service to inspect the bits, apart from having to reject PCBs which are incorrectly drilled due to the initial damage of the bits.